CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - Unaudited - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Distributions In Excess Of Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interest in Joint Ventures
BALANCE at Dec. 31, 2017	$ 751,130	$ 3	$ 1,061,153	$ (317,032)	$ 5,348	$ 1,658
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28,748	0	0	28,713	0	35
Net unrealized change in fair value of cash flow hedges	3,606	0	0	0	3,606	0
Common dividends declared	(22,388)	0	0	(22,388)	0	0
Stock-based compensation, net of forfeitures	1,044	0	1,044	0	0	0
Issuance of common stock, common stock offering, net of expenses	14,602	0	14,602	0	0	0
Issuance of common stock, dividend reinvestment plan	54	0	54	0	0	0
Withheld shares of common stock to satisfy tax withholding obligations in connection with the vesting of restricted stock	(2,055)	0	(2,055)	0	0	0
Distributions to noncontrolling interest	(65)	0	0	0	0	(65)
BALANCE at Mar. 31, 2018	774,676	3	1,074,798	(310,707)	8,954	1,628
BALANCE at Dec. 31, 2018	904,703	4	1,222,547	(326,193)	6,701	1,644
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	22,534	0	0	22,529	0	5
Net unrealized change in fair value of cash flow hedges	(2,313)	0	0	0	(2,313)	0
Common dividends declared	(26,520)	0	0	(26,520)	0	0
Stock-based compensation, net of forfeitures	1,447	0	1,447	0	0	0
Issuance of common stock, common stock offering, net of expenses	24,400	0	24,400	0	0	0
Issuance of common stock, dividend reinvestment plan	54	0	54	0	0	0
Withheld shares of common stock to satisfy tax withholding obligations in connection with the vesting of restricted stock	(2,788)	0	(2,788)	0	0	0
Distributions to noncontrolling interest	(43)	0	0	0	0	(43)
BALANCE at Mar. 31, 2019	$ 921,474	$ 4	$ 1,245,660	$ (330,184)	$ 4,388	$ 1,606